Apparatus for synchronizing the speed of strip sampling punch and continuously travelling strip



Jan. 29, 1963, I R. A. @Hum 3,075,419

APPARATQS FOR SYNCHRONIZING THE SPEED OF STRIP SAMPLING PUNCH AND CONTINUOUSLY TRAVELLING STRIP Filed July 24, 1959 5 Sheets-Sheet'l 1 o O O O 0 Il l i I7/ F1|; l FHS-Z /NVENTR ROBERT A. SCHULTZ Attorney Jan. 29, 1963 @Hum 3,075,419

R. A. S APPARATUS FOR SYNCHRONIZING THE SPEED OF STRIP SAMPLING PUNCH ANDv CONTINUOUSLY TRAVELLING STRIP Filed July 24, 1959 5 Sheets-Sheet 2 vE/v ron Rose-' As scm/L rz Allarm?) Jan. 29, 1963 R. A. scHuL'rz 3,075,419

APPARATUS FOR SYNCHRONIZING THE SPEED OF STRIP SAMPLING PUNCH AND CONTINUOUSLY TRAVELLING STRIP Filed July 24, 1959 3 sheets-sheet 3 FHEHE INVE/VZ'OR HUBER 7' A. SCHUL TZ A Harney United States Patent O 3,075,419 APPARATUS FOR SYNCHRONIZING THE SPEED F STRIP SAMPLING PUNCH AND CONTINU- OUSLY TRAVELLING STRIP Robert A. Schultz, Pittsburgh, Pa., assgnor to United States Steel Corporation, a corporation of New Jersey 'Filed July 24, 1959, Ser. No. 829,379 2 Claims. (Cl. 83-295) This invention relates to apparatus for taking samples from continuously travelling metal strip, and is directed to a speed synchronizing apparatus in the form of a mechanical drive that extends between yand is adapted to connect the travelling strip and -a strip sampling punch for synchronous movement.

It relates more particularly to a strip sampling apparatus of the type covered by the co-pending application of Alfred Teplitz, Serial No. 827,287, filed July 15, 1959.

Quality-control in the manufacture of tin plate as well as other sheet metal strip products requires that samples be taken frequently for testing in the mill metallurgical laboratories. If the product is sheared into sheets, sampling is easily accomplished by periodically removing sheets from the conveyor belt following the shear. However, if the product is produced in coil form, samples can be readily obtained only from the ends of the coil and such samples, moreover, may not be accurately representative of the product in other portions of the coil. For the purpose of quality control it is highly desirable that samples should be taken from the strip at points other than its ends. Stopping of the line to obtain samples from the body of the coil is impractical since this would interfere with the strip processing operation and render portions of the strip, for example, those portions in plating tanks during the stoppage, of unsuitable quality.

The above mentioned application of Alfred Teplitz discloses an apparatus that operates to take samples from strip at it travels through a processing line and which does not require stoppage or slowing of the strip movement. In a preferred embodiment of such apparatus,

kthe strip has its movement guided over a vertical path that extends through a punch carriage, which is mounted for gravitational acceleration along said path from an elevated position. The desired sample is removed from the strip by a punch and die that are arranged on opposite sides of .the strip and are mounted on the punch carriage for movement between retracted and punching positions relative to each other Iand the strip. After downward movement of the punch carriage is accelerated vto a speed that is synchronized with the speed of strip travel, the punch and die are actuated by camming units that are arranged in the path of downward movement of the punch carriage.

In order that the strip will not be mutilated by tearing or the formation of burrs `about the holes formed by punching samples from the strip, there must be no relative movement between the strip and the punch when the punch is operated to remove the sample, and this requires precise speed synchronization of .the punch carriage with the speed of strip travel, and a punching operation that is performed while such speeds are synchronized. This invention accordingly has as one of its principal objects the provision of an interconnecting drive for synchronizing the movement of a punch and the strip from which a sample is to be taken.

drive there is provided an over-running clutch that has one part that is continuously rotated at a speed corresponding to the speed of strip travel, a second part that is rotated at a speed corresponding to the speed of the punch carriage, and sprags that lock the two rotating parts together when the punch carriage connected second part tends to rotate at a speed greater than the first or strip connected part.

A strip sampling apparatus of the character referred to generally above as shown in the drawings further includes a hoist for raising the punching carriage to an elevated position from which it is released for gravitational movement in the direction of strip travel, a clamping mechanism for securing the punch carriage to the strip during its downward movement, and a camming mechanism that operates to perform the punching operation, which are respectively directed to the end of speed synchronization and punching a sample from the strip when there is no relative movement that would damage the strip. Such hoist, clamping and camming mechanisms involve inventions which are covered in my copending applictions as follows: Serial No. 829,380, tiled July 24, 1959; and Serial No. 837,418, `tiled September 1, 1959.

Other objects and advantages of the invention will become apparent from the following description and the accompanying drawings in which:

FIGURE 1 is an elevational view of a strip sampling apparatus constru-cted in accordance with the principles of this invention;

FIGURE 2 is an elevational view looking from the right of FIGURE 1;

FIGURE 3 is an enlarged fragmentary elevational view of a portion of the apparatus shown in FIGURE 2 which shows the punch-frame assembly thereof in an elevated position;

FIGURE 4 is a plan view of the structure shown in FIGURE 3;

FIGURE 5 is an elevational view looking from the left of FIGURE 3;

FIGURE 6 is a fragmentaryvertical sectional view showing somewhat diagrammatically an over-running clutch that forms part of the drive for controlling the vertical movement of the punch-frame lassembly shown in the preceding figures; and

FIGURE 7 is a fragmentary sectional view taken substantially in the plane of the line VII-VII of FIG- URE 6.

The strip punching apparatus shown in FIGURES 1-5, generally stated, comprises a punch-frame assembly 1 which is mounted for vertical movement with respect to a frame 2, a hoist unit 3 that controls the raising and `lowering movements of the assembly 1, and a pair of For this purpose and according to a preferred embodiment movement of the carriage at a greater speed.r In such camming units 4 respectively arranged in the path of vertical movement vof opposite ends of the assembly 1 for operating it to effect a strip punching operation. The strip S travels continuously over guide rolls 5, 6 and 7 and moves downwardly over a vertical path between Ithe guide rolls 6 and 7 that extends through the punch assembly 1. To effect a strip punching operation, lthe hoist unit 3 is operated to elevate the punchframe assembly 1 from its lowered position, shown in FIGURES 1 and 2, to its elevated position, shownv in FIGURE 3, where it is released for gravitational downward movement in the direction of strip travel between the guide rolls 6 and 7. As the assembly 1 moves downwardly, the camming units 4 operate punch and die devices, which as described in the above mentioned co-pending applications form part of the assembly 1 and are respectively positioned on opposite sides of the strip S, to effect a strip punching operation. The as- 3 sembly 1, as best shown in FIGURE 4, comprises a carriage in the form of a rectangular frame which has its vertical movement guided by guide collars 9 extending inwardly from opposite ends thereof. The collars 9 have sliding engagement on vertical guide rods l@ that have bolted `connections with vertical standards 11, which, as best shown in FIGURE 2, are arranged along opposite edges of the vertical path of movement f the strip S and form part of the frame 2. The cammlng units 4 are secured in facing relation along the inner sides of the standards 11.

As indicated above, raising and lowering movement of the frame assembly 1 is controlled by the hoist unit 3, which includes (see FIGURE 3) a winding drum 12 for a hoist cable 13 connected at its lower end to the punchframe carriage 8. The drum 12 is mounted for rotation by a shaft 14 which is supported in bearings 15 and is driven by an electric hoist motor 16 through a sprocket 'chain drive 17. Upon operation of the motor 16, the drum 12 is rotated to wind the cable 13 thereon and raise the punch-frame assembly 1 to the elevated position shown in FIGURE 3. As the assembly 1 moves into this position, a limit switch 18, which controls rotation of the drum 12 by the shaft 14, is actuated to discontinue the upward movement of the assembly 1 and release it forV gravitational movement downwardly over the guide rods 1G. The hoist unit 3 further includes mechanism providing for' axial cable threading movement of the drum 12 to maintain the cable 13 centered with respect to the assembly 1 which forms the subject matter of my co-pending application, Serial No. 837,418, mentioned above, and to which reference is made for a detailed description thereof. While the drum 12 in the preferred construction of the unit 3`is connected and released with respect to the drive shaft 14 through magnetic clutches (not shown), the drive shaft 14 can be regarded for the purpose of this invention as being continuous through the bearings and the drum 12 as having a keyed connection thereto such that raising and lowering movement of the assembly 1 is controlled by the energized condition of the motor 16. In this respect, it will be understood that lthe limit switch 18 can be regarded as controlling the energization of the motor 16 and, more particularly, as operating to de-energize it to release the drum 12 for a 'gravitational lowering movement of the assembly 1.

In order that the strip will not be torn or mutilated when the punching operation is eiected, the assembly 1 must have a downward speed, when it is opposite the camming units 4 and a strip punching operation is effected thereby, that exactly matches the speed of travel of the strip S. Synchronization of the speed of movement of the assembly 1 and the strip S is essential in order that there will be no relative vertical movement between the strip and the punch and die parts of the assembly 1 when they operate to punch a sample from the strip S. The speed synchronization for this purpose is in accordance with the principles of this invention preferably accomplished through a drive that includes an over-running clutch 19 which forms part of the hoist unit 3. The clutch 19 is conventional and is illustrated somewhat diagrammatically in FIGURES 6 and 7 of the drawings as comprising an inner race 20 connected by a key 21 to the shaft 14, and an outer race 22 supported for rotation on the outer end 23 of the shaft 14. The outer race 22 is rotated continuously in a counterclockwise direction, as viewed in FIGURE 7, by a chain and sprocket drive which includes a sprocket 25 keyed to the outer race 22, a sprocket 26 connected with the strip guide roll 6 for rotation therewith, and a sprocket-chain 2'7 connecting the sprockets 25 and 26. Since the guide roll 6 has frictional engagement with the strip S and is thus driven at a speed corresponding to the linear speed of strip movement, the outer race 22 is continuously driven at a rotational speed corresponding to the linear speed of strip travel. The over-running feature of the clutch 19 is provided by clutch wedges or sprags 23 between the inner race 2t) and the outer race 22 which operate to prevent rotation of the inner race 2d in a counterclockwise direction, as viewed in FIGURE 7, at a rotational speed greater than the rotational speed of the outer race 22. In this manner, the over-running clutch 19 provides for unrestricted relative rotation of thevinner race 2G and shaft 14 in a clockwise direction, as viewed in FIGURE 7, to permit elevation of the frame assembly 1, and to permit its downward acceleration by gravity to a speed correspending to the speed of strip travel. When the assembly and strip speeds are matched, the clutch sprags 23 operate to lock the inner race Ztl to the outer race 22 and prevent the inner race 2t) from over-running the outer race 22 so that further increase in the speed of downward movement of the assembly 1 is prevented. For this purpose, the unit 3 must be constructed to provide for locking operation of the sprags 23 at the instant when the strip speed and the peripheral speed of the drum 12 are the same. The vertical elevation from which the assembly 1 is dropped by actuation of the limit switch 18 must be sufciently high that the assembly 1 is accelerated to a speed matching the strip speed prior to its movement to the level of the camming units 4. When the assembly 1 reaches the speed at which the strip S is travelling, the clutch 19 operates through the sprags 2S as explained to prevent further increase in speed of the assembly 1.

From the foregoing it will be apparent that the drive of this invention acting through the over-running clutch 19 operates to synchronize the downward movement of the assembly 1 with the strip S, and that this is accomplished at different speeds o strip travel. In this respect, it will be noted for slow speeds of strip movement the sprags 28 operate to lock the inner and outer races 29 and 22 against relative movement at an early point in the downward movement of the assembly 1, while for higher strip speeds the sprags 2S operates at a later point in the downward movement of the assembly 1. Attention is particularly directed to the fact that the speed synchronizing action of the clutch 19 enables a stationary location of the limit switch 18 so that the punch-frame assembly 1 is released for downward movement at a xed elevation for all speeds of strip travel, and the switch 1S may thus be attached to one of the standards 11 in the position shown in FIGURE 2.

A pair of shock absorbers Sti stop the downward movement of the carriage when it reaches the position shown in FIGURE 2. The shock absorbers Sti are engaged by a pair of bumpers 51 that are secured to the carriage 8 of the assembly 1.

While the carriage S of the punch-frame assembly 1 is mounted for vertical movement in the preferred embodiment of the invention as described above, and thus utilizes gravity for accelerating its speed to the speed of strip movement, it will be understood that the principles of this invention are applicable to modications in which, for example, the punch-frame carriage 8 is mounted for horizontal movement and has a power drive for accelerating its speed to the speed of strip travel.

While one embodiment of my invention has been shown and described it will be apparent that other adaptations and modications may be made without departing from the scope of the following claims.

I claim:

l. In punching apparatus for taking samples from strip travelling continuously over a vertical path, the combination comprising a carriage mounted for gravitational acceleration along said path, and means controlling the movement of said carriage comprising a cable having one end attached to said carriage, a drum on which the other end of said cable is wound, said drum being rotatable by said cable in response to gravitational lowering of said carriage, a speed sensing roller engaged with the strip moving over said vertical path and continuously rotated thereby, and a mechanical drive differentially connecting said roller and drum including an over-running clutch having a iirst element connected with said roller for rotation thereby, a second element connected with said drum for rotation thereby, and over-running clutch means for preventing said second element over-running said rst element and thereby gravitational movement of said carriage at a speed greater than the speed at which the strip is travelling.

2, In a punch for taking samples from continuously travelling strip, the combination With a strip processing line including strip conveyor means for continuously delivering strip over a rectilinear path, of a carriage mounted for accelerated movement along said path in the direction of strip movement, and means controlling the accelerated movement of said carriage comprising a cable having one end attached to said carriage, a drum on which the other end of said cable is wound, said drum being ro-tatable by said cable in response to acceleration of said carriage, a speed sensing roller engaged with' the strip moving over said path and continuously rotated thereby, and a mechanical drive differentially connecting said roller and drum including an over-running clutch having a first element connected with said roller for rotation thereby, a second element connected with said drum for rotation thereby, and overrunning clutch means for preventing said second element over-running said first element and thereby movement of said carriage at a speed greater than the speed at which the strip is travelling.

References Cited in the le of this patent UNITED STATES PATENTS 1,304,426 Welch May 20, 1919 2,519,159 Talbot Aug. l5, 1950 2,578,825 Mireld et al Dec. 18, 1951 2,746,126 Talbot May 22, 1956 

1. IN PUNCHING APPARATUS FOR TAKING SAMPLES FROM STRIP TRAVELLING CONTINUOUSLY OVER A VERTICAL PATH, THE COMBINATION COMPRISING A CARRIAGE MOUNTED FOR GRAVITATIONAL ACCELERATION ALONG SAID PATH, AND MEANS CONTROLLING THE MOVEMENT OF SAID CARRIAGE COMPRISING A CABLE HAVING ONE END ATTACHED TO SAID CARRIAGE, A DRUM ON WHICH THE OTHER END OF SAID CABLE IS WOUND, SAID DRUM BEING ROTATABLE BY SAID CABLE IN RESPONSE TO GRAVITATIONAL LOWERING OF SAID CARRIAGE, A SPEED SENSING ROLLER ENGAGED WITH THE STRIP MOVING OVER SAID VERTICAL PATH AND CONTINUOUSLY ROTATED THEREBY, AND A MECHANICAL DRIVE DIFFERENTIALLY CONNECTING SAID ROLLER AND DRUM INCLUDING AN OVER-RUNNING CLUTCH HAVING A FIRST ELEMENT CONNECTED WITH SAID ROLLER FOR ROTATION THEREBY, A SECOND ELEMENT CONNECTED WITH SAID DRUM FOR ROTATION THEREBY, AND OVER-RUNNING CLUTCH MEANS FOR PREVENTING SAID SECOND ELEMENT OVER-RUNNING SAID FIRST ELEMENT AND THEREBY GRAVITATIONAL MOVEMENT OF SAID CARRIAGE AT A SPEED GREATER THAN THE SPEED AT WHICH THE STRIP IS TRAVELLING. 